syms x z t alpha
INT1 = int(-3*x/(1+x^2)^3)
INT2 = int(x/(1+z^3),z)
INT3 = int(INT2,x)
INT4 = int(x*log(2+x),0,1) 
INT5 = int(2*x, sin(t), 2) 
INT6 = int([exp(t),exp(alpha*t)])
